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Friday, 25 March 2016

Covenanter: Reservist Tank

Winston Churchill's saying "The tank that carries my name has more drawbacks than I do!" in regards to the Infantry Tank Mk.IV is well known. Despite this evaluation, the Churchill was the longest-living British tank, even finding itself useful in Korea. It is not know what the Prime Minister thought about the Cruiser Tank Mk.V, more known as the Covenanter, but there is one fact that says more than enough: it is the most numerous tank of the Second World War that never saw combat.

In a Hurry

The increase in armour of the Cruiser Tank Mk.III that resulted in the Cruiser Tank Mk.IV was a half-measure, unable to radically improve the combat effectiveness of the tank. The British Ministry of War knew that the modernization reserve of this chassis ran out. A deep modernization was necessary to make the tank meet the expectations of the military, and fast.

The Ministry of War, and especially one of the minds behind the cruiser tank concept, Lieutenant Colonel Giffard Le Quesne Martel, did not sit still. In 1936, specifications were developed for a "heavy" cruiser tank. Martel was inspired by the T-28 tanks he saw alongside BT tanks during Soviet exercises. Interestingly enough, the T-28 was initially inspired by the three turreted British Medium Tank Mk.III.

Two companies got to work: Nuffield Mechanization & Aero and the London Midland & Scottish Railway Company (LMS). LMS began work on the A14 heavy cruiser tank, which was indeed similar to a T-28. Nuffield chose a different direction. Their result was more similar to the experimental T-29. Even though the difference in weight between the two tanks was about 9 tons, the characteristics were similar. By 1939, one prototype of both the A14 and A16 was built. Neither the military nor the developers were particularly impressed with them. The result was the same cruiser tanks, but bigger, slower, and more expensive.

Pilot prototype of the Cruiser Mk.V, fall of 1940. The hull machinegun is a distinctive feature of this design.

On February 2nd, 1939, specifications for a new cruiser tank were developed. The maximum thickness of its armour was 40 mm. The Christie suspension was preserved, and the same 2-pounder (40 mm) gun and BESA machinegun were used. The combat weight of the tank was supposed to be about the same as that of the A13 vehicles (Cruiser Tank Mk.III and Mk.IV). Seeing these requirements, Nuffield and LMS themselves asked the Ministry of War to cancel the heavy cruiser tanks, since thickening their armour served no purpose. Another vehicle was needed, a much lighter one.

Work on the new tank, indexed A13 Mk.III, was assigned to three companies. LMS was working on the hull and chassis, Nuffield was designing the turret. A third company, Henry Meadows, was tasked with the engine. This decision was made due to the negative feedback that came from users of the Nuffield-Liberty engines. However, the participation in the A13 Mk.III project didn't mean that Nuffield gave up on their own tank. Instead of the rejected A16, work began on the lighter A15 vehicle.

The A13 Mk.III project was ready in mid-April of 1939. Instead of a deep modernization, LMS ended up with a brand new tank which inherited only the suspension type from its predecessor. Even this component was not exactly the same. LMS engineers installed the springs on an angle in order to make the hull lower. Overall, the hull was not only lower, but shorter than its predecessor.

Thanks to the angled suspension elements, the Covenanter's hull was very low.

The low hull was made possible by the 16 Liter DAV engine developed by Henry Meadows. This 12 cylinder 300 hp engine was designed using the opposite layout, which allowed reduction of the height of the engine compartment. The Wilson planetary transmission was paired with this engine.

The aim to make a compact and low hull conflicted with common sense. There was no room for cooling radiators in the engine compartment, so LMS engineers didn't think of anything better than moving them to the front of the hull. The radiators were placed on the left side of the tank, and the driver was displaced to the right. The air vents for the radiators were in the most important place from the point of view of armour protection, and even though there was a deflector that protected the vents from the front, its effectiveness was negligible. It's worth mentioning that the radiators were cooled by fans which were powered by the turret traverse motor. There was also no room in the engine compartment for air filters, which were instead moved to the engine compartment roof and protected with light covers.

Meadows DAV opposite engine which made height reduction possible.

The original plan was to make the hull fully welded, but even by early summer of 1939, it was obvious that there would not be enough skilled welders. LMS was forced to redesign their hull, which increased in mass by 100 kg. Instead of welding, rivets were used as much as possible, which was only natural for a locomotive company. Another feature was layered armour. The armour was composed of two plates without any space between them. For example, the front plate was composed of a 21 mm plate and a 19 mm one, with the inner plate being made from mild steel.

The turret, designed by Nuffield, also had its oddities. On one hand, the armour was sloped. On the other hand, for some reason only the rear and sides were. The front of the turret remained at an almost right angle. The oddities did not end there. Someone clever in Nuffield decided that there is no reason to have a commander's cupola, so it was replaced with a Mk.IV periscope. This periscope was installed right in the middle of the turret, right above the gun breech. Of course, it could be used somehow, but when the gun fires right under the commander's chin, it must have been rather uncomfortable. There was another periscope on the right side of the turret for the loader.

The turret hatch was also interesting. There was only one, but it was large. During travel, the hatch could be flipped back and used as a seat. Aside from a 2-pounder gun and a BESA machinegun, the turret also had a 2" (50.8 mm) breech-loaded mortar for firing smoke grenades.

Cruiser Tank Mk.V production at the LMS factory. April, 1941.

Despite the unusual decisions made during the design process, the tank was deemed satisfactory by the Ministry of War. On April 17th, 1939, LMS received a contract to make 100 tanks with serial numbers ranging from T.7095 to T.7194. No prototype was to be built, and the tank would enter production immediately. However, later, a T.7195 pilot tank was built after all.

English Electric and Leyland Motors were going to be involved in the production starting in September of 1939. The first received a contract for 100 tanks (T.15295-T.15394) and the second for 151 tanks (T.15395-T.15545). The A13 Mk.III was accepted into service as the Cruiser Tank Mk.V before the first tank was even built.

This rush can be easily explained. Say what you will about Chamberlain and his actions in Munich, but he did buy Britain a year of peace. It is fair to say that this year proved decisive for Britain, including Britain's tank production. In fall of 1938 there was simply nothing to fight with. The production of new tanks was just getting off the ground, and the majority of the armoured forces was composed of 4 ton tanks equal to the Pz.Kpfw. I. The British military had to take a risk.

Reliability? Never heard of it

During the construction of the first Cruiser Tank Mk.V, it became clear that the Wilson transmission was a no go. Instead, it was replaced with a stock Meadows gearbox from the Cruiser Tank Mk.IV and combined with the Wilson planetary turning mechanism. This introduced additional problems connected with cooling. Another loss was the decision to not use an aluminium alloy for the road wheels. Even though each wheel weighed 10 kg less than a pure steel one, sacrifices had to be made in the name of simplicity.

Covenanter I from the 1st Armoured Division during Exercise Bumper, September 1941.

The pilot tank T.7195 had both aluminium road wheels and a Wilson transmission. Turning was done with a steering wheel as opposed to levers. The engine compartment size was increased compared to mass production models, which had a positive effect on the engine cooling. The first two tanks also had a hull machinegun, presumably so the driver wouldn't be bored during battle.

The experimental tank arrived sans turret to the Farnborough proving grounds on May 23rd, 1940. It travelled 802 miles (1283 km) during trials, reaching a speed of up to 60 kph. Since it had experimental cooling equipment, no problems with overheating were observed. Later, an experimental Merritt-Brown transmission was installed on the tank, and it drove another 839 miles (1342 km).

The real problems began when the second tank, T.7095, arrived on September 29th, 1940. Aside from the driver's machinegun, this vehicle was exactly identical to mass production models. After 50 minutes of driving, the water temperature in the cooling system was 75 degrees Celsius. After 2.5 hours, the temperature reached 177 degrees! The oil cooling system was also overheating, and there were problems with the gearbox.

A common pastime for Covenanter crews. This "lucky" Covenanter I crew belongs to the 9th Armoured Division.

Attempts to correct the situation resulted in delays. The first tanks only left the factory in late December, and only 7 units were finished that year. They were sent directly to Bovington, where they took part in military trials. A torrent of unkind words followed. The compact layout of the engine compartment resulted in problems during service. There were also complaints about the fighting compartment, which was found equal to that of the competitor Cruiser Tank Mk.VI, which was already in use by the military at the time.

Both tanks had problems with the suspension. Since 242.5 mm wide 102 mm long track links migrated from the lighter Cruiser Tank Mk.IV, the ground pressure increased and the lifetime of the tracks decreased. Work began on 272 mm wide 103 mm long track links, which reduced the ground pressure by 10% and reduced the amount of links per track from 120 to 114. Later, a third type of track link was developed, made with different materials and with different track pins.

Covenanter II from the 9th Armoured Division, 1942. The radiator cooling vents have been redesigned.

Despite the fact that problems with the cooling system were not corrected, the production of the tank was not cancelled. LMS, Leyland, and English Electric made 81 tanks in the first quarter of 1941, 186 tanks in the second quarter, and 212 in the third. These still weren't the volumes that the Ministry of War was looking for. The army's requirement for cruiser tanks alone was 9930 units in January of 1941. Contracts for production of the tank named Covenanter in spring of 1941 were handed out in abundance. Strangely, LMS produced the fewest tanks. Aside from the aforementioned 100 units, it only built 60 more (T.81347-T.81406).

English Electric built the following series of tanks:

T.18361-T.18660 (300 tanks)

T.18661-T.18760 (100 tanks)

T.78244-T.78346 (103 tanks)

T.81407-T.81446 (40 tanks)

T.81447-T.81612 (166 tanks)

T.81613-T.81862 (250 tanks)

T.130695-T.130719 (25 tanks)

In total, English Electric built a little over half of all Covenanter tanks. In parallel with tanks, this famous company also built Hampden and Halifax bombers.

Nominally a car company, Leyland also built A27L Centaur and then Centurion tanks. As for the Covenanter, the company carried out the following contracts:

T.23104-T.23203 (100 tanks)

T.81863–81902 (40 tanks)

T.81903-T.81962 (60 tanks)

T.81963-T.82087 (125 tanks)

T.130720-T.130769 (50 tanks)

The last contract was signed in August of 1941, but production went on for a lot longer. The Cruiser Tank Mk.V, Covenanter I, remained in production until the fall of 1941. 500 units were built. Tanks from the early series had the same gun mantlet as the Cruiser Tank Mk.IVA. Later tanks received an improved mantlet that was protected from being jammed by shells.

Covenanter tanks took part in may experiments. For instance, amphibious equipment was tested on this model.

Production of the Covenanter III began in October of 1941. Most of the differences in this model were in the rear of the hull. The tank received improved air filters and a radically redesigned engine compartment, which improved the situation with cooling. This was the most numerous modification: 680 tanks were built. Later models received an external fuel tank, mounted in the rear.

LMS was not particularly saddened by the small amount of tanks it built, as in April of 1942, it began modernization of Covenanter I tanks. The tanks received an improved cooling system, improved air filters, and other equipment, making the life of their crews merely difficult instead of nightmarish. These modernized tanks were indexed Covenanter II, and some of which were converted into Covenanter IICS tanks.

Covenanter III tank from the 9th Armoured Division on exercises, 1942. It is easy to see how the rear of the hull is significantly different from tanks of other modifications.

The last modification, Covenanter IV, went into production in June of 1942. The hull was similar to Covenanters I and II. This modification used a third type of air filters, the same types as used on late Crusader models. The tanks continued to use 2-pounder guns, while Crusader and Cavalier tanks already had 6-pounder (57 mm) guns. There are suspicions that the Ministry of War was already aware of the Covenanter's limited future and didn't want to install expensive new guns on it. Some tanks were converted into Covenanter IVCS tanks with 3" howitzers.

The last Covenanter tanks were produced in early 1943. In total, 1771 Covenanter tanks of all types were built. 20 Covenanter I and 60 Covenanter IV tanks were converted into Covenanter Bridgelayers.

Training Tank

The first unit to receive the Cruiser Tank Mk.V was the 1st Armoured Division. Its tankers already had a go at the Light Tank Mk.VII, which they rejected. The new cruiser tank also caused little joy. In September of 1941, the 1st Armoured Division participated in Exercise Bumper. At their conclusion, the division handed off their tanks to receive Crusaders and left for North Africa.

Covenanter Bridgelayer on trials, 1943. According to Peter Brown's research, this is a conversion of the first prototype of the A13 Mk.III.

The 9th Armoured Division "inherited" the Covenanters. It was formed in December of 1940 as a training unit. The Covenanter was received with enthusiasm at first. This is not surprising, as the unit previously had worn out Cruiser Tank Mk.IV tanks, which weren't famous for their reliability to begin with. This enthusiasm didn't last long, and many complaints about breakdowns were sent to the manufacturers. Tankers of the 9th Armoured Division were forced to endure the Covenanter until September of 1942 when they were replaced with Centaurs.

The Irish Guards also received Covenanter tanks, this time the reliable Covenanter III, which they kept until September of 1943. In May of 1943, this unit participated in Exercise Columbus.

Winston Churchill using a Covenanter III from the 9th Armoured Division as a podium, May 1942.

The last to receive these unlucky vehicles were the Poles. In 1942, the 1st Polish Armoured Division was formed, armed with Valentine and Covenanter tanks. The only "combat" loss of a Covenanter was in this unit. As a result of a night raid by German aircraft on Canterbury in Kent County, a bomb hit a tank that was a part of an armoured train. Covenanter tanks served with the Poles until early 1944.

The 1st Polish Tank Division was the last to use Covenanter tanks. This photo was taken in early 1944.

Due to many problems with the cooling system, the Covenanter never reached the battlefield. To be fair, Crusader tanks weren't exceptional in this regard either, and the Covenanter eventually surpassed its competitor. In July of 1942, during comparative trials, the Covenanter managed to drive for 1600 km, while the Crusader engine only lived for 1120 km. Likely as a result, the military risked sending four Covenanter IV tanks with sand shields to Africa. These tanks were never used in combat and remained at the training camp in Abbasiyah (north-west of Cairo). It's likely that their technical problems never went away.

The only known photo of Covenanter tanks in Africa, March 1943. The tank is in its usual state: undergoing maintenance.

The Covenanter was written off in February of 1944. Nobody particularly cared about these tanks, and only one survives to this day. This is a Covenanter III T.23140, produced by Leyland in later 1941. The vehicle with a personal name "Achilles" was a part of the 9th Armoured Division. It spent several decades at a junkyard, after which it ended up in the Bovington tank museum. In addition, two Covenanter Bridgelayer vehicles survived to our time.